Manifolding system for engines



H. H. TXMEAN Jan. 26, 1932.

MANIF'JLDING SYSTEM FOR ENGINES Filed Feb. 8, 1929 2o manifold of circular cross section.

Patented Jan. 26, 1932 Ulti'l" STATES PATENT OFFICE HAROLD H. TIMIAN, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO VIHEELER-SCI-IEBLER CARBURETOR COMPANY, OF INDIANAPOLIS, INDIANA, A CORPGRATION OF INDIANA MANIFOLDING SYSTEM FOR ENGINES Application filed February 8, 1929.

This invention relates to an improved form of intake manifold for internal combustion engines operating under a widely varying range of speed and load.

It is the principal object of this invention to provide an intake manifold adapted to supply an equal division of a wet fuel and air mixture to a plurality of intake ports which may be and often are, at unequal distances from the carburetor.

In the operation of an engine under idling conditions of very low manifold velocities, the heavier drops of liquid fuel tend to follow the stream flow in the manifold as the low velocity is not conducive to centrifugal action. As the volume of flow is correspondingly light, the flow cuts corners and the precipitated or liquid fuel tends to follow the inner surface or radius of a bend'in a The liquid fuel is thus discharged nearer one port than another, the lirstanentioned port thus receiving more than its share of the heavy ends comprising the bulk of the liquid in the manifolds. Under full power and speeds, on the other hand, the manifold velocities are very high with the consequent development of centrifugal action which throws liquid fuel particles to the outer surface or radius of the bend, thus reversing the fuel supply conditions mentioned with regard to idling conditions. It is accordingly an ob j ect of this invention to correct the fuel distribution by correlating the wall contours of a manifold cross section immediately preceding a branch or point of division in the manifold.

t is a further object of this invention to provide an elongated passageway having a nozzle-like cross section adapted to promote reintroduction of liquid fuel deposited on the manifold walls into the air stream.

It is also an object of this invention to provide an improved manifold of the type described for multicylinder engines wherein the various branches are so constructed as to facilitate proper division and reintroduction of liquid fuels at each dividing point in the manifold.

Other and further important objects of Serial No. 338,373.

this invention will be apparent from the disclosures in the specification and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure 1 is a top plan view of a manifold embodying the features of this invention.

Figure 2 is a vertical section on the line IIII of Figure 1.

Figure 3 is a cross section on the line TIL-III of Figure 2.

Figure 4 is a top plan view of a simple form of manifold embodying the features of this invention.

Figure 5 is a section on the line V-V of Figure 4.

As shown 011 the drawings:

Inasmuch as a conventional carburetor has an outlet passage of circular cross section, the main intake pipe 10 terminates in a conventional carburetor mounting flange as shown at 10 with a fragment of a carburetor 11 secured thereto. The intake pipe 10 gradu ally changes in section until it becomes an elongated passage 12 adjacent the point of juncture with the manifold 13 which distributes the mixture to the difierent cylinders. The pipe 10 is shown as vertical in Figures 1 and 2, while it is shown horizontal in Figures 4 and 5, as both arrangements are commonly used and do not affect the present invention.

In Figures 1 and 2 a series of six intake ports are to be supplied by individual branch outlets 14 which are provided with flanges 15 for bolting to the cylinder block. The ports are normally circular in section thus defini11 the corresponding shape of the branch outlets. As shown, two adjacent outlets may be joined by a common sub-manifold branch 16 having a nozzle-like connection '17, corresponding to the elongated passage 12, to another manifold branch 18 also connected to a third of the branch outlets 14, the manifold branch 18 in turn having an elongated nozzle-like connection 19, to one end of the manifold 13. The other three ports are supplied with fuel by a similar arrangement of manifold branch from the other end of the manifold 13.

The nozzle-like passages 12, 17, and 19 are alike in configuration, being so designed as to throw off liquid traveling along the walls so that the liquid will be restored to the air stream substantially centrally thereofto assure proper division between the branches. The simple form of manifold of Figures i and;5 utilizesahorizontalintakepipe :10 terminating :in .a nozzle-like elongated pa 20 of the same general form which opens into a manifold branch 21 supplying itwo branch outlets 22.

In the description. of=the operation ofthe manifold of this invention, it will be more convenientto first consider the inan'ifoldnf Figures 4 and 5. The usual characteristics of a fuel andair mixture include bothentrainedfuel. droplets carried by the air stream, and a film of liquid flowing along the walls of the manifold and maintained .by accumulation of fuel droplets deposited on the walls r condensed out of the air stream. The .fuel wetting the manifold walls flows at a more sluggish rate than the air mixture, hence the need of anaccelerating pump, w ien the throttle is opened wide, in order to add more fuel to the air stream to temporarily compensate for the fuel delayedfby'flowing along thewalls.

Under idling conditions the fuel carried as droplets in the air stream tends to follow the stream and to cut corners at'the bends because of the lack of centrifu al action a thereon at low air speeds. 'Thus in Figure 5, the fuel will hug the right side of the bend at the nozzle 21 and if the passage were of the same area at the dividing point as elsewhere, apreponderanceof fuel would reachthe right hand port. Under full throttle conditions on the other hand, the fuel would be thrown to the outer or left hand wall of thebend due to centrifugalaction in the rapidly moving air stream, so that the left hand port would then get more than its share of the liquid fuel. According to the present invention, the -noz z'le-like restricted passage opening into the manifold branches at each point of division of the air stream serves to promote reintroduction of fuel fractions subject to inertia forces, at a point midway between the outlet ports. The action of the nozzle-like passage centers the fuel in the air stream regardless of Whether it is thrown out on one wall or the other, and it has a similar action on fuel flowing along the walls of the manifold. Figures i and 5 illustrate only a single bend Whereas in adapting this invention to multicylinder engines, use is made of these nozzle-like passages at each point of stream division .as is shown in Figure 1 for the case of a six cylinder engine.

I am aware that numerous details of the invention may be -varied through a wide range without departing from the spirit of this invention, and I do not desire limiting the patent granted other than as necessitated by the prior art.

I claim as my invention:

1. A manifold for multicylinder engines comprising axcarburetor connection, a manifold branch connected thereto by an elongated passage of restricted area with the axis of ithe passageat right angles to the branch,

. and. a plurality of'inlet port connections simtake passage dividing .into branches serving individual intake :ports, .and narrow relatively long passageways at each point oil-division into branches whereby to reintroduce precipitated fuel into .the air stream.

in testimony whereof :I have hereuntosubscribed my name at Indianapolis, Ind., county, Marion.

HAROLD H. TIMIAN. 

